The study aims at the building of the first normalized language assessment test intended for French-speaking preschoolers living in African countries where language delays are ignored and where there is a lack of public services in speech-language therapy. Being inspired by the format of standardized language tests, and based on language acquisition theories, we developed a tool named Batterie de tests de dépistage approfondi (BATEDA) which combine eleven tests organized in three batteries assessing respectively modalities (BATEM), language components (BATEL) and memory (TMV). From a sample of 159 Cameroonian French-speaking four-to-five-years old children, the tool has been normalized using standard scores technique (the z score and the percentile). Tests have an inter-scorer reliability, an internal consistency of 96% (α de Cronbach=0,958) and a predictive validity of the primary school success of children (r=0,700). The application strategies of BATEDA aim at encouraging the screening of language delays in order to take charge of these difficulties in Cameroon by implicating teachers and parents as main participants. Among the implications of this study, we have the better knowledge of difficulties related to language delays, the better consideration of children affected, the establishment of early screening and language assessment on behalf of intervention, and a potential decrease of the rate of school abandon and expulsion of children with language delays.